diff --git a/tcn_hpl/data/utils/pose_generation/generate_pose_data.py b/tcn_hpl/data/utils/pose_generation/generate_pose_data.py
index 9fb24ae03..428dc3dca 100755
--- a/tcn_hpl/data/utils/pose_generation/generate_pose_data.py
+++ b/tcn_hpl/data/utils/pose_generation/generate_pose_data.py
@@ -324,6 +324,11 @@ def predict_coco(
             img = read_image(img_path, format="BGR")
             boxes, scores, classes, keypoints_list = self.predict_single(img)
 
+            # boxes is output in xyxy (ltrb), but the COCO format wants xywh
+            # format.
+            boxes[:, 2] -= boxes[:, 0]
+            boxes[:, 3] -= boxes[:, 1]
+
             # We will need non-numpy data types to insert into the structure to
             # follow JSON compliance.
             boxes_list = boxes.tolist()